JP2004345518A - Travel control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure safe travel when an impact for changing the detection range is applied to a sensor for recognizing an object in front of one's own vehicle, in the vehicle having a vehicle control means for controlling travel of the own vehicle based on the relative positional relation between the own vehicle and an object in front of it. <P>SOLUTION: When it is detected that the impact for changing the detection range is applied to the front-object sensor, an amount of the optical axis displacement of the front-object sensor by the impact (a displacement amount of the vehicle from the longitudinal axis) is estimated. When the optical axis displacement amount is larger than a predetermined value, the travel control by the vehicle control means is inhibited. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle travel control device that performs travel control in accordance with a relative positional relationship with an object ahead of a host vehicle.
[0002]
[Prior art]
In a conventional vehicle travel control device, when a stationary object (a forward roadside delineator) is detected by a sensor that recognizes an object in front of the host vehicle, the movement trajectory is statistically processed, and the optical axis of the sensor is processed. It is known to detect a shift amount (a shift amount of a vehicle from the front-rear axis direction) and correct relative position information with respect to a front object based on the optical axis shift amount (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-10-132939
[0004]
[Problems to be solved by the invention]
However, in the above-described conventional vehicle travel control device, since the optical axis shift of the sensor is detected by statistically processing the movement trajectory of the stationary object, the actual shift of the optical axis may be considerably increased. It cannot be detected until the time has elapsed. Therefore, when an optical axis shift occurs due to a light collision or the like, there is an unsolved problem that the system operates with the optical axis shifted until the optical axis shift is detected.
[0005]
Therefore, the present invention has been made by focusing on the unsolved problem of the above conventional example, and when a shift occurs in a detection range of a sensor for recognizing an object ahead of the host vehicle, the shift is immediately detected. It is an object of the present invention to provide a vehicular travel control device capable of performing the following.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a vehicular travel control device according to the present invention includes a shock detection means for detecting that an impact having a change in a detection range is applied to a front object detection means, and a front object detection for the front object detection means. When it is detected that an impact has been applied to the means, the travel control inhibiting means inhibits travel control by the travel control means.
[0007]
【The invention's effect】
According to the present invention, when it is detected that an impact is applied to a sensor for recognizing an object ahead of the host vehicle and the detection range is changed, the traveling control is immediately prohibited. It is possible to reliably prevent the running control from being performed without being able to accurately recognize the position, and to ensure the safe running.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a first embodiment will be described.
FIG. 1 is a schematic configuration diagram showing an embodiment in which the present invention is applied to a rear wheel drive vehicle equipped with a collision speed reduction device. In the drawing, 1FL and 1FR are front wheels as driven wheels, 1RL and 1RR are The rear wheels 1RL, 1RR, which are driving wheels, are driven to rotate by the driving force of the engine 2 being transmitted via the automatic transmission 3, the propeller shaft 4, the final reduction gear 5, and the axle 6.
[0009]
Each of the front wheels 1FL, 1FR and the rear wheels 1RL, 1RR is provided with a brake actuator 7 which is constituted by, for example, a disc brake for generating a braking force, and the brake hydraulic pressure of these brake actuators 7 is controlled by a brake control device 8. Is done.
Here, the braking control device 8 generates a braking oil pressure in response to the depression of a brake pedal (not shown), and generates a braking pressure command value P from the traveling control controller 20._BR, And generates a braking hydraulic pressure in accordance with the braking force, and outputs the generated braking hydraulic pressure to the brake actuator 7. Further, a vehicle speed sensor 13 for detecting the own vehicle speed Vs by detecting the rotation speed of an output shaft provided on the output side of the automatic transmission 3 is provided.
[0010]
On the other hand, a front object sensor 14 as a front object detecting means is provided below the vehicle body on the front side of the vehicle, and is periodically shifted by a scanning angle at a predetermined angle in the horizontal direction by a scanning laser radar. Is irradiated with fine laser light within a predetermined irradiation range (for example, 12 ° to 24 ° in the horizontal direction, 4 ° in the vertical direction), receives reflected light reflected from an object in front and returned, and emits light. As shown in FIG. 2, the relative distance dr between the host vehicle MC and the front object PC at each angle is detected based on the time difference from the time to the reception timing of the reflected light. The relative speed Vr between the front object and the host vehicle is calculated from the temporal change in the detected relative distance dr to the front object, and the traveling direction of the host vehicle is determined based on the detection signal of the front object sensor 14 and its scanning angle. The angle range θ of the left and right edges of the front object with respect to the reference_RAnd θ_LIs detected.
[0011]
The front object sensor 14 is usually attached by a fastener or the like with a high precision whose optical axis direction is within an allowable error range (for example, ± 0.5 °) from the longitudinal axis of the vehicle. If the optical axis direction of the sensor deviates to the left or right beyond the allowable error range from the longitudinal axis of the host vehicle due to impact or the like, the obliquely forward object is erroneously recognized as the object in front of the host vehicle and deviates vertically. It is not possible to accurately detect the relative positional relationship with the front object, for example, because it cannot recognize the front object.
[0012]
Further, the vehicle is provided with an acceleration sensor 15 for detecting a longitudinal acceleration Xg generated in the host vehicle, and a yaw rate sensor 16 for detecting a yaw rate φ generated in the host vehicle. Further, an optical axis deviation display device 17 is provided in the vehicle interior, and when the optical axis deviation of the front object sensor 14 is detected and an optical axis deviation notification command is input from the traveling controller 20, the driver receives an optical axis deviation. Present the state of axis misalignment.
[0013]
The own vehicle speed Vs output from the vehicle speed sensor 13, the relative distance dr output from the front object sensor 14, the relative speed Vr, and the angle range θ_R, Θ_L, The acceleration Xg output from the acceleration sensor 15 and the yaw rate φ output from the yaw rate sensor 16 are input to the traveling control controller 20, and the traveling control controller 20 causes the vehicle speed sensor 13, the front object sensor 14, the acceleration sensor 15, It is determined whether or not an impact that changes the detection range has been applied to the front object sensor 14 based on a signal input from any one of the yaw rate sensor 16 and the yaw rate sensor 16, and the optical axis shift amount Δθ of the front object sensor 14 is determined. presume. Further, the traveling control controller 20 determines that the relative distance dr with respect to the front object detected by the front object sensor 14 is equal to the braking control operating distance d set based on the optical axis deviation amount Δθ._SETIn the following cases, the braking pressure command value P_BRTo the braking control device 8 to permit the braking control of the own vehicle.
[0014]
Next, a description will be given with reference to FIG. 3 showing a braking control operation determination processing procedure in which the operation of the first embodiment is executed by the traveling control controller 20.
This braking control operation determination processing is executed as a timer interruption processing every predetermined time (for example, 10 msec). First, in step S1, the relative distance dr detected by the front object sensor 14, the relative speed Vr, and the angle range θ_R, Θ_LRead.
[0015]
Next, the process proceeds to step S2, in which an impact in which the detection range to the front object sensor 14 changes is detected in an impact determination process described later, and the braking control prohibition determination and the braking control working distance d are performed._SETIs set, and the process proceeds to step S3.
In step S3, the brake control prohibition flag F set in step S2 is set._CAIs set to "1" indicating that control is prohibited, and whether or not automatic braking is inactive is determined._CAIf = 1 and the automatic braking is not in operation, the process proceeds to step S4 to prohibit the operation of the braking control, terminates the timer interrupt process, and returns to the predetermined main program.
[0016]
If the determination result of step S3 is F_CAWhen = 0 or during the automatic braking operation, the process proceeds to step S5, and it is determined whether or not the own vehicle is traveling in the braking control permission area. This determination is based on the fact that the relative distance dr to the forward object is equal to the braking control working distance d set in step S2._SETIs performed depending on whether or not_CA= 0 and dr> d_SETWhen it is determined that the vehicle is traveling in the braking control prohibition region, the process proceeds to step S4. On the other hand, in other cases, the process proceeds to step S6, and it is determined whether or not collision with the forward object can be avoided by the driver's braking operation.
[0017]
In step S6, it is determined whether or not the relative distance dr and the relative speed Vr read in step S1 have a relationship represented by the following equation (1). If the following formula (1) is not satisfied, it is determined that collision avoidance by braking is possible, and the routine proceeds to step S7, where the braking collision avoidance flag F_BIs set to “1”. On the other hand, if the following equation (1) is satisfied, it is determined that collision avoidance by braking is impossible, and the routine proceeds to step S8, and the braking collision avoidance flag F_BIs reset to “0”.
[0018]
dr <−Vr · Td + Vr²/ 2a (1)
Here, Td is a dead time until deceleration occurs at the time of a driver's brake operation, and a is a deceleration generated by the driver's brake operation.
Next, it is determined whether or not a collision with a forward object can be avoided by the driver's steering operation. First, in step S9, a lateral movement amount necessary for avoiding steering is calculated. When the host vehicle MC and the forward object PC have a relationship as shown in FIG. 4, the lateral movement amount Y required to avoid steering to the right._RAnd the lateral movement amount Y required to avoid steering to the left._LAre as shown in the following equations (2) and (3), respectively.
[0019]
Y_R= Dr tan θ_R−dr · tan ｛1/2 · sin^-1(Φ / Vs)｝ + W_b/ 2 + W_S  ............ (2)
Y_L= −dr · tan θ_L+ Dr · tan ｛1/2 · sin^-1(Φ / Vs)｝ + W_b/ 2-W_S  ……… (3)
Here, as shown in FIG._RIs the angle range of the right end of the front object detected by the front object sensor 14, θ_LIs the angular range of the left end of the front object detected by the front object sensor 14, W_bIs the width of the vehicle, W_SIs the offset amount of the sensor mounting position from the own vehicle center.
[0020]
The lateral movement amount Y required for steering avoidance is the lateral movement amount Y required for steering avoidance to the right._RAnd the amount of lateral movement Y required to avoid steering to the left_LSelect and set the smaller of.
Y = min (Y_R, Y_L) ...... (4)
Here, min () is a function for selecting the smaller one in parentheses.
[0021]
Next, the process proceeds to step S10, where the lateral movement amount Y shown in FIG. 5 and the lateral movement time T shown in FIG._yThe time required for steering avoidance based on the relationship T_yIs calculated, and the process proceeds to step S11. In FIG. 5, the horizontal axis represents the amount of lateral movement Y required to avoid steering, and the vertical axis represents the time T required for lateral movement._yThe time T required for the lateral movement increases as the lateral movement amount Y required to avoid the operation increases._yIs also set to increase.
[0022]
In step S11, it is determined whether the following equation (5) is satisfied. If the following equation (5) is not satisfied, it is determined that collision avoidance by steering is possible, and the routine proceeds to step S12, where the steering collision avoidance flag F is set._SIs set to “1”. On the other hand, if the following equation (5) is satisfied, it is determined that collision avoidance by steering is impossible, and the routine proceeds to step S13, where the steering collision avoidance flag F is set._SIs reset to “0”.
[0023]
dr <Vr · T_y  ……… (5)
Next, in step S14, it is determined whether collision avoidance by braking is not possible and collision avoidance by steering is not possible._BIs "0" indicating that collision avoidance is impossible, and the steering collision avoidance flag F_SIs "0" indicating that collision avoidance is not possible, the process proceeds to step S15, and automatic braking is operated for a predetermined time and with a predetermined magnitude. On the other hand, if the determination result of step S14 is F_B= 1 or F_SIf = 1, the flow shifts to step S16 to cancel the automatic braking.
[0024]
As shown in FIG. 6, in the impact determination process of step S2, first, in step S201, it is determined whether or not an impact that causes a change in the detection range of the front object sensor 14 has occurred. The determination of the impact is performed based on the acceleration signal Xg detected by the acceleration sensor 15. When the acceleration sensor 15 detects the deceleration equal to or more than the predetermined value, it is determined that an impact having a magnitude causing the optical axis shift has occurred. Further, it is determined that the larger the deceleration is in the negative direction, the larger the optical axis deviation is, and the optical axis deviation amount Δθ is estimated based on the deceleration detected by the acceleration sensor 15 with reference to a map as shown in FIG. Then, the optical axis shift amount Δθ is stored. In FIG. 7, the horizontal axis represents the absolute value of the deceleration, and the vertical axis represents the optical axis deviation Δθ, and the optical axis deviation Δθ is set to change linearly with the deceleration.
[0025]
Next, the process proceeds to step S202, and it is determined whether or not the optical axis adjustment of the front object sensor 14 is performed. If the optical axis adjustment has not been performed at the maintenance shop, the store, or the like, the process shifts to step S203 to hold the stored optical axis shift amount Δθ, and then shifts to step S205 described later. On the other hand, if the result of the determination in step S202 is that the optical axis adjustment has been performed, the process proceeds to step S204 to reset the stored optical axis deviation amount Δθ to “0” and to display the optical axis deviation display device. After the optical axis shift display of No. 17 is not displayed, the process proceeds to step S205.
[0026]
In this step S205, the optical axis shift amount Δθ is equal to the optical axis shift display threshold Δθ._SETIt is determined whether or not Δθ ≧ Δθ_SETIf so, the flow shifts to step S206 to display the optical axis shift state on the optical axis shift display device 17, and then shifts to step S207, where Δθ <Δθ_SETIf so, it is determined that the previous display state is maintained, and the process directly proceeds to step S207.
[0027]
In step S207, the optical axis deviation amount Δθ is equal to the predetermined value Δθ_TH2It is determined whether or not Δθ ≦ Δθ_TH2If it is, the process proceeds to step S208 and the braking control prohibition flag F_CAIs reset to “0” indicating control permission, and the braking control working distance d is changed according to the optical axis deviation amount Δθ as shown in FIG._SETSet. Braking control working distance d_SETIs that the optical axis deviation amount Δθ is a predetermined value Δθ_TH1When the distance is equal to or less than the above, the same distance range d as in the state where there is no optical axis shift₁Fixed to Δθ_TH1<Δθ ≦ Δθ_TH2, The larger the optical axis deviation is, the shorter the distance is set, and Δθ = Δθ_TH2And the distance range d₂Is set to
[0028]
On the other hand, when the determination result of step S207 is Δθ> Δθ_TH2If so, the flow shifts to step S209, where the braking control prohibition flag F_CAIs set to “1” representing control prohibition.
In the process of FIG. 3, the processes of steps S3 and S4 correspond to the traveling control prohibiting unit, and the processes of steps S6 to S13 correspond to the collision avoidance determining unit. In the process of FIG. 6, the process of step S201 corresponds to an impact detection unit, the processes of steps S205 and S206 correspond to a detection range change notification unit, and the processes of steps S207 to S209 correspond to a travel control change unit. ing.
[0029]
Therefore, it is assumed that the own vehicle is traveling with the automatic braking inactive. In this state, a certain impact is applied to the own vehicle, and the predetermined value Δθ is applied to the front object sensor 14._TH2When a larger optical axis shift occurs, in the impact determination process of FIG. 6, the acceleration sensor 15 detects a value equal to or more than a predetermined value in the deceleration direction in step S201, and the predetermined value Δθ_TH2A larger optical axis shift amount Δθ is estimated. Since the optical axis adjustment is not performed at the maintenance shop or the store, the process shifts from step S202 to step S203, and the stored optical axis deviation amount Δθ is retained, and the optical axis deviation amount Δθ is the optical axis deviation display threshold Δθ._SETBecause of the above, the process proceeds to step S206 according to the determination in step S205, and the optical axis shift display device 17 displays the optical axis shift. And Δθ> Δθ_TH2Therefore, the process proceeds from step S207 to step S208, and the braking control prohibition flag F_CAIs set to “1” representing control prohibition. F_CA= 1 and the own vehicle is not under automatic braking, so in the braking control operation determining process of FIG. 3, the process proceeds from step S3 to step S4 to prohibit automatic braking, and travel according to the driver's accelerator and brake operation. To continue.
[0030]
Further, when the own vehicle is running with the automatic braking in the operating state, a certain impact is applied to the own vehicle, and the predetermined value Δθ_TH2When a larger optical axis shift occurs, in the impact determination process of FIG. 6, the process proceeds from step S207 to step S208, and the braking control prohibition flag F_CAIs set to “1” representing control prohibition. Since the own vehicle is being automatically braked, the process proceeds from step S3 to step S5 in the brake control operation determination process of FIG. F_CASince = 1, the process proceeds to step S6 based on the determination in step S5 to determine whether the driver can avoid braking, and then determines whether the driver can avoid steering. When it is determined that it is possible to avoid either of the braking avoidance and the steering avoidance, the process proceeds from step S14 to step S16, in which the automatic braking is released and the traveling is performed according to the driver's accelerator and brake operations. . Therefore, after that, Δθ> Δθ until the optical axis adjustment is performed._TH2State is continued and F_CA= 1 and the automatic braking non-operation state, so that the process shifts from step S3 to step S4 to prohibit automatic braking and continue running according to the driver's accelerator and brake operations. That is, the forward object sensor 14 detects the braking control working distance d._SETThe following relative distance dr is detected, and even when the own vehicle is traveling in the braking control permission area, the automatic braking is prohibited and the traveling according to the driver's accelerator and brake operation is continued. Will be.
[0031]
As described above, when it is determined that an impact that causes an optical axis shift has occurred, the optical axis shift amount Δθ is estimated, and the optical axis shift amount Δθ is set to a predetermined value Δθ._TH2Since the automatic braking is prohibited when the distance is larger, it is possible to reliably prevent the traveling control from being performed in a state in which the relative positional relationship with the front object cannot be accurately recognized due to the optical axis deviation.
On the other hand, the predetermined value Δθ_TH2In the state where the following slight optical axis deviation occurs, the relative distance dr between the host vehicle and the object ahead is the braking control operating distance d._SETIt is assumed that the vehicle is traveling in a braking control prohibition region exceeding. In this case, first, in the impact determination process of FIG. 6, in step S201, Δθ ≦ Δθ_TH2Is estimated. Since the optical axis adjustment is not performed at the maintenance shop or the store, the process shifts from step S202 to step S203, and the stored optical axis deviation amount Δθ is retained, and the optical axis deviation amount Δθ is changed to the optical axis deviation display threshold Δθ._SETIf the above is the case, the process proceeds to step S206 based on the determination in step S205, and the optical axis deviation display device 17 displays the optical axis deviation. Then, the process proceeds from step S207 to step S209, and the braking control prohibition flag F_CAIs reset to “0” indicating control permission, and the distance range corresponding to the optical axis deviation amount Δθ is set to the braking control operation distance d as shown in FIG._SETIs set as F_CA= 0 and dr> d_SETTherefore, in the braking control operation determination process of FIG. 3, the process shifts from step S5 to step S4 to prohibit automatic braking, and travel according to the driver's accelerator and brake operations.
[0032]
After that, the relative distance dr to the forward object is equal to the braking control working distance d._SETIn the following, when the vehicle is traveling in the braking control permission area, the braking control can be performed so as to suppress the own vehicle from approaching the front object. F_CA= 0 and dr ≦ d_SETTherefore, the process proceeds from step S5 to step S6 to determine whether or not the driver can avoid the braking, and then determine whether or not the driver can avoid the steering. If it is determined that it is possible to avoid either the braking avoidance or the steering avoidance, the process proceeds from step S14 to step S16, and the traveling according to the driver's accelerator and brake operation is continued.
[0033]
On the other hand, when it is determined that the braking avoidance and the steering avoidance are impossible, the process shifts from step S14 to step S15, and the braking pressure command value P such that a predetermined hydraulic pressure is generated._BRIs output to the braking control device 8 to shift to the braking control of the own vehicle.
Here, the braking control working distance d_SETIs set to a smaller value as the optical axis shift amount Δθ is larger._TH1<Δθ ≦ Δθ_TH2In the case of, the braking control is performed only on the object whose relative positional relationship with the forward object is closer as compared with the case where there is no optical axis deviation.
[0034]
As described above, in the first embodiment, when a certain impact is applied to the own vehicle and the mounting position of the sensor for recognizing an object in front of the own vehicle shifts, the detection range of the sensor changes. Detecting this immediately and prohibiting the operation of the braking control when the host vehicle is not automatically braking can reliably prevent the travel control from operating while the detection range of the sensor is changed. When the vehicle is in the middle, it is determined whether the driver can avoid the braking and the steering, and only when it is determined that the collision can be avoided, the operation of the braking control is released. Therefore, safe driving can be ensured.
[0035]
Further, as the amount of change in the detection range of the sensor for recognizing an object ahead of the host vehicle is larger, the braking control is performed only on the object having a closer relative positional relationship with the detected object ahead. Since the braking control is also performed for a distant relative positional relationship with the detected front object as compared with the case where the amount is large, the position of the front object can be detected without deteriorating the accuracy of the front object position, Optimal braking control can be performed according to the state of change of the detection range.
[0036]
In addition, since the magnitude of the impact applied to the front object sensor is detected using the acceleration signal of the acceleration sensor used for airbags, which are widely used, a new sensor for detecting the impact is installed. It is not necessary to carry out, and cost increase can be reduced.
In the first embodiment, the case where the acceleration sensor is applied as the acceleration detecting means has been described. However, the present invention is not limited to this, and the acceleration may be calculated from the vehicle speed of the own vehicle detected by the vehicle speed sensor. It may be.
[0037]
Next, a second embodiment of the present invention will be described.
In the second embodiment, in the first embodiment described above, the determination of the impact in which the detection range of the front object sensor 14 changes is performed using the signal of the yaw rate sensor 16.
FIG. 9 is a flowchart showing a processing procedure of an impact determination process executed by the travel control controller 20 in the second embodiment. In the impact determination process of the first embodiment shown in FIG. Except that the processing is replaced with the processing of step S221 of detecting an impact having a magnitude that causes an optical axis shift and estimating the optical axis shift amount Δθ based on the change rate of the yaw rate φ detected by the yaw rate sensor 16. 6 are performed, and the same parts as those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0038]
According to the second embodiment, in step S221, the change rate of the yaw rate φ detected by the yaw rate sensor 16 is calculated, and if the absolute value of the calculated value is equal to or greater than a predetermined value, the light It is determined that an impact that causes axis misalignment has occurred. Further, it is determined that the larger the absolute value of the calculated value is, the larger the optical axis shift is, and the optical axis shift amount Δθ based on the change rate of the yaw rate φ is estimated with reference to a map as shown in FIG. After the axis deviation amount Δθ is stored, the process proceeds to step S202 described above. In FIG. 7, the horizontal axis represents the absolute value of the rate of change of the yaw rate φ, and the vertical axis represents the optical axis deviation Δθ, and the optical axis deviation Δθ changes linearly with respect to the absolute value of the rate of change of the yaw rate φ. It is set as follows.
[0039]
As described above, in the second embodiment, the magnitude of the impact applied to the front object sensor is detected using the yaw rate signal of the yaw rate sensor which is also used as a sensor for recognizing the front object. It is not necessary to newly install a sensor for detecting an impact, so that cost increase can be reduced.
Next, a third embodiment of the present invention will be described.
[0040]
The third embodiment is different from the first embodiment described above in that the determination of an impact in which the detection range of the front object sensor 14 changes is performed using the signal of the vehicle speed sensor 13.
FIG. 10 is a flowchart illustrating a processing procedure of an impact determination process executed by the traveling control controller 20 in the third embodiment. In the impact determination process of the first embodiment illustrated in FIG. The processing is replaced by the processing of step S231 in which the impact of a magnitude causing the optical axis deviation is detected and the optical axis deviation amount Δθ is estimated based on the change rate of the own vehicle speed Vs detected by the vehicle speed sensor 13. Except for this point, the same processing as in FIG. 6 is performed, and the same parts as those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0041]
According to the third embodiment, the change rate of the own vehicle speed Vs of the vehicle speed sensor 13 is calculated in step S231, and when the calculated value is equal to or more than a predetermined value in the deceleration direction, the optical axis deviation is detected by the forward object sensor 14. It is determined that an impact that causes the occurrence of is generated. Further, it is determined that the larger the calculated value is in the deceleration direction, the larger the optical axis deviation is, and the optical axis deviation amount Δθ based on the change rate of the vehicle speed is estimated with reference to a map as shown in FIG. After the axis deviation amount Δθ is stored, the process proceeds to step S202 described above. In FIG. 7, the horizontal axis represents the absolute value of the change rate of the own vehicle speed Vs, and the vertical axis represents the optical axis shift amount Δθ. The optical axis shift amount Δθ is linear with respect to the absolute value of the change rate of the own vehicle speed Vs. Set to change.
[0042]
As described above, in the third embodiment, the magnitude of the impact applied to the front object sensor is detected using the own vehicle speed change rate of the vehicle speed sensor used in most vehicles, so that a new impact is detected. There is no need to install a sensor for detection, and cost increase can be reduced.
Next, a fourth embodiment of the present invention will be described.
[0043]
In the fourth embodiment, in the first embodiment described above, the determination of the impact in which the detection range of the front object sensor 14 changes is performed using the signal of the front object sensor 14.
FIG. 11 is a flowchart showing a processing procedure of an impact determination process executed by the travel control controller 20 in the fourth embodiment. In the impact determination process of the first embodiment shown in FIG. The processing is replaced with the processing of step S241 in which an impact having a magnitude that causes an optical axis shift is detected based on the relative distance dr and the relative speed Vr detected by the front object sensor 14 and the optical axis shift amount Δθ is estimated. Except for this, the same processing as in FIG. 6 is performed, and the same parts as those in FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0044]
According to the fourth embodiment, when the relative distance dr detected by the front object sensor 14 is equal to or less than the predetermined value in step S241, it is determined that a collision that causes the optical axis deviation of the front object sensor 14 has occurred. to decide. Further, it is determined that the larger the relative speed Vr in the approaching direction at that time is, the larger the optical axis shift is, and the optical axis shift amount Δθ based on the relative speed in the approaching direction is estimated with reference to a map as shown in FIG. After that, the optical axis shift amount Δθ is stored, and then the process proceeds to step S202 described above. In FIG. 7, the horizontal axis represents the relative speed Vr in the approaching direction, and the vertical axis represents the optical axis deviation amount Δθ. The optical axis deviation amount Δθ is set to linearly change with respect to the relative speed Vr in the approaching direction. You.
[0045]
As described above, in the fourth embodiment, since the magnitude of the impact applied to the front object sensor is detected using the detection value of the front object sensor, it is necessary to newly install a sensor for detecting the impact. And cost increase can be greatly reduced.
In the fourth embodiment, a case has been described where it is determined that an impact that causes an optical axis shift has occurred when the relative distance to the front object is equal to or less than a predetermined value. In step S14, when it is impossible to avoid collision by braking and collision avoidance by steering, and when automatic braking is being performed, it is determined that an impact has occurred in the sensor for recognizing a forward object after the automatic braking ends. You may make it. In this case, when the relative speed is greater than or equal to a predetermined value in the approaching direction, it is determined that an impact that causes an optical axis shift has occurred, and it is determined that the optical axis shift increases as the relative speed in the approaching direction increases. do it. This makes it possible to estimate that a collision has occurred even if the state in which it is impossible to detect a forward object after detecting a state in which collision avoidance is not possible. The occurrence of an impact can be more reliably detected.
[0046]
Next, a fifth embodiment of the present invention will be described.
In the fifth embodiment, the present invention is applied to a rear-wheel drive vehicle equipped with an inter-vehicle distance control device.
That is, as shown in FIG. 12, a schematic configuration in the fifth embodiment is provided with an engine output control device 11 for controlling the engine output, and the front object sensor 14 having the scanning type configuration in the first embodiment described above. Instead, a forward object sensor 18 having a radar system configuration is provided, and the target vehicle speed is set so that the inter-vehicle distance becomes the target inter-vehicle distance when the vehicle in front of the host vehicle is being captured, instead of the travel control controller 20. To control the own vehicle speed and set the own vehicle speed Vs to the set vehicle speed V set by the driver when the vehicle in front of the own vehicle is not captured._SET1 has the same configuration as that of FIG. 1 except that a follow-up controller 30 is provided, and the same reference numerals are given to portions corresponding to FIG. 1 and detailed description thereof is omitted.
[0047]
The front object sensor 18 has a radar type configuration that sweeps laser light in a predetermined irradiation range (for example, 9 ° in the horizontal direction and 3 ° in the vertical direction) and receives reflected light from the preceding vehicle. An inter-vehicle distance D between the vehicle and the preceding vehicle is detected. Then, the relative speed ΔV between the preceding vehicle and the host vehicle is calculated from the temporal change of the inter-vehicle distance D.
The front object sensor 18 is usually attached to the front of the vehicle by fasteners or the like with a high precision whose optical axis direction is within an allowable error range (for example, ± 0.5 °) from the longitudinal axis of the vehicle. If the direction of the optical axis of the sensor deviates from the longitudinal axis of the host vehicle to the left or right beyond the allowable error range due to some impact on the vehicle, the vehicle traveling diagonally ahead in the adjacent lane If the vehicle is misrecognized as a vehicle ahead of the lane, and if it shifts up and down, the preceding vehicle cannot be recognized, and the relative positional relationship with the preceding vehicle cannot be accurately detected.
[0048]
The own vehicle speed Vs output from the vehicle speed sensor 13, the inter-vehicle distance D output from the front object sensor 18, the relative speed ΔV, the acceleration Xg output from the acceleration sensor 15, and the yaw rate φ output from the yaw rate sensor 16 follow-up control. This signal is input to the controller 30, and the tracking control controller 30 controls the front object sensor 18 based on a signal input from any one of the vehicle speed sensor 13, the front object sensor 18, the acceleration sensor 15, and the yaw rate sensor 16. It is determined whether or not an impact that changes the detection range has been applied, and the optical axis shift amount Δθ of the front object sensor 18 is estimated. In addition, the following controller 30 sets the target vehicle speed so that the inter-vehicle distance becomes the target inter-vehicle distance while capturing the vehicle ahead of the traveling lane of the own vehicle, and controls the own vehicle speed. The vehicle speed V when the vehicle in front of the lane is not captured_SIs the set vehicle speed V set by the driver_SETPressure command value P to be controlled_BRAnd target throttle opening θ^*Is output to the braking control device 8 and the engine output control device 11.
[0049]
The tracking control controller 30 includes a microcomputer and its peripheral devices, and forms a control block shown in FIG. 13 in the form of software of the microcomputer.
The control block measures a time from when the front object sensor 18 sweeps the laser beam to when the reflected light of the preceding vehicle is received, and calculates a distance D between the vehicle and the preceding vehicle. The inter-vehicle distance D is calculated based on the inter-vehicle distance D, the own vehicle speed Vs, and the relative speed ΔV calculated by the distance measurement signal processing unit 21 to obtain the target inter-vehicle distance D.^*Target vehicle speed V to maintain_L ^*And the target vehicle speed V calculated by the following distance control unit 40_L ^*Drive shaft torque T based on_W ^*And a target drive shaft torque T calculated by the vehicle speed control unit 50._W ^*Throttle opening command value θ for the throttle actuator 12 and the brake actuator 7 based on the_RAnd braking pressure command value P_BRAnd a drive shaft torque control unit 60 that outputs these to the throttle actuator 12 and the brake actuator 7.
[0050]
The inter-vehicle distance control unit 40 calculates a target inter-vehicle distance D between the preceding vehicle and the own vehicle based on the preceding vehicle speed Vt calculated from the own vehicle speed Vs and the relative speed ΔV.^*And a target inter-vehicle distance D calculated by the target inter-vehicle distance setting section 42^*And the target inter-vehicle distance D based on the inter-vehicle distance D input from the ranging signal processing unit 21 and the own vehicle speed Vs.^*Target vehicle speed V to match_L ^*Is calculated.
[0051]
Here, the target inter-vehicle distance setting unit 42 calculates a target inter-vehicle distance during a following operation of the preceding vehicle at a constant vehicle speed and a constant inter-vehicle distance, that is, a steady target inter-vehicle distance D between the preceding vehicle and the own vehicle.^*Is calculated. In this embodiment, in order to keep the inter-vehicle time constant, the steady target inter-vehicle distance D is calculated by the following equation (6).^*Is calculated.
D^*= Vt × Th (6)
Here, Vt is the preceding vehicle speed, and Th is the inter-vehicle time.
[0052]
The inter-vehicle distance control calculation unit 43 calculates the inter-vehicle distance D based on the inter-vehicle distance D and the relative speed ΔV.^*Target vehicle speed V for following the preceding vehicle while maintaining_L ^*Is calculated based on the following equation.
V_L ^*= K_L(DD^*) + K_V(ΔV−ΔV^*) + Vt (7)
Where K_LIs the inter-vehicle distance control gain, K_VIs a relative speed control gain.
[0053]
When the vehicle is in the following control state, the target vehicle speed V input from the following distance control unit 40 when the preceding object sensor 18 is capturing the preceding vehicle._L ^*And the set vehicle speed V set by the driver_SETThe smaller of the target vehicle speed V^*And when the preceding vehicle is not captured, the set vehicle speed V set by the driver_SETIs the target vehicle speed V^*And a target vehicle speed V set by the target vehicle speed setting unit 51.^*Target drive shaft torque T for matching own vehicle speed Vs to_W ^*Is calculated.
[0054]
Further, the drive shaft torque control unit 60 calculates the target drive torque T_W ^*Throttle opening command value θ to achieve_RAnd brake fluid pressure command value P_BRAnd the throttle opening command value θ_RIs output to the engine output control device 11 and the brake fluid pressure command value P_BRIs output to the braking control device 8.
The inter-vehicle distance control unit 40, the vehicle speed control unit 50, and the drive shaft torque control unit 60 constitute a travel control unit.
[0055]
Further, the target vehicle speed setting section 51 executes a target vehicle speed setting process shown in FIG.
This target vehicle speed setting process is executed as a timer interrupt process for each predetermined time (for example, 10 msec). First, in step S101, the target vehicle speed Vs detected by the vehicle speed sensor 13 and the preceding vehicle detected by the front object sensor 18 are compared. The inter-vehicle distance D is read, and then the process proceeds to step S102, in which an impact that changes the detection range to the front object sensor 18 is detected in an impact determination process described later, and the inter-vehicle distance control prohibition determination and the inter-vehicle distance detection limit D are performed._MAXMake the settings for
[0056]
In step S103, it is determined whether or not the following running control is being performed. This determination is based on the fact that the preceding object sensor 18 has detected the preceding vehicle and the inter-vehicle control inhibition flag F set in step S102._CAIs reset to “0” indicating control permission, and the inter-vehicle distance D detected by the front object sensor 18 is set to the inter-vehicle distance detection limit D set in step S102._MAXIt is determined whether or not:_CA= 0 and D ≦ D_{M AX}If, the preceding vehicle is detected, and it is determined that the follow-up running control is being performed, and the process proceeds to step S104.
[0057]
In step S104, the target vehicle speed V calculated by the inter-vehicle distance control calculation unit 43 according to the above equation (7)._L ^*And the set vehicle speed V set by the driver_SETAnd compare the smaller value with the target vehicle speed V^*And then proceeds to step S105, where the target vehicle speed V^*Is input to the target drive shaft torque calculation unit 53, and then the timer interrupt process is terminated and the process returns to the predetermined main program.
[0058]
V^*= Min (V_L ^*, V_SET) ……… (8)
Here, min () is a function for selecting the smaller one in parentheses.
On the other hand, when the determination result of step S103 is F_CA= 1 or D> D_MAXWhen it is determined that the vehicle is in the inter-vehicle distance control prohibited state or the preceding vehicle is not detected, the process proceeds to step S106, and the set vehicle speed V set in advance by the driver is determined._SETIs the target vehicle speed V^*Then, the process proceeds to step S105.
[0059]
FIG. 15 is a flowchart showing the procedure of the optical axis deviation determination processing in step S102. In the impact determination processing in the first embodiment shown in FIG. 6, the processing in steps S208 and S209 is performed based on the headway distance detection limit D_MAX6 except that the process is replaced with the process of step S251 for prohibiting inter-vehicle distance control and the process of S252 for prohibiting the inter-vehicle distance control, and the same parts as those in FIG. Is omitted.
[0060]
In step S207, the optical axis shift amount Δθ is equal to the predetermined value Δθ._TH2It is determined whether or not Δθ ≦ Δθ_TH2If so, the flow shifts to step S251, where the inter-vehicle control prohibition flag F_CAIs reset to “0” indicating control permission, and the inter-vehicle distance detection limit D is changed according to the optical axis deviation Δθ as shown in FIG._MAXSet. On the other hand, when the determination result of step S207 is Δθ> Δθ_TH2If so, the flow shifts to step S252, where the inter-vehicle control prohibition flag F_CAIs set to "1" indicating control prohibition so that the following distance control is not activated.
[0061]
Therefore, it is assumed that the own vehicle is traveling at a maintenance shop, a store, or the like in a state where the optical axis is adjusted and the optical axis deviation does not occur in the front object sensor 18. In this case, in the shock determination process of FIG. 15, the process shifts from step S202 to step S204 to reset the stored optical axis shift amount Δθ to “0” and to reset the optical axis shift display device 17 to the optical axis shift. Hide the display. Since the optical axis shift amount Δθ is 0, the flow shifts from step S207 to step S251, and the headway control prohibition flag F_CAIs reset to "0" indicating control permission, and the inter-vehicle distance D is set as shown in FIG.₁Is the inter-vehicle distance detection limit D_MAXIs set as When the host vehicle does not detect the preceding vehicle, the front object sensor 18 detects the following distance D_MAXSince the larger inter-vehicle distance D is detected, in the target vehicle speed setting process of FIG. 14, the process proceeds from step S103 to step S106, and the set vehicle speed V set by the driver is set._SETIs the target vehicle speed V^*And then proceeds to step S105, where the target vehicle speed V^*Is input to the target drive shaft torque calculation unit 53, and thereby the own vehicle speed Vs is set to the set vehicle speed V set by the driver._SETThe traveling control is performed so as to match with.
[0062]
From this state, a certain impact is applied to the own vehicle, and a predetermined value Δθ is applied to the front object sensor 18._TH2If a larger optical axis shift occurs, in the impact determination process of FIG. 15, a value equal to or more than a predetermined value is detected in the deceleration direction in step S201, and the predetermined value Δθ_TH2A larger optical axis shift amount Δθ is estimated. Next, the process proceeds from step S202 to step S203, where the stored optical axis shift amount Δθ is held, and the optical axis shift amount Δθ is set to the optical axis shift display threshold value Δθ._SETBecause of the above, the process proceeds to step S206 according to the determination in step S205, and the optical axis shift display device 17 displays the optical axis shift. And Δθ> Δθ_TH2Therefore, the process proceeds from step S207 to step S208, and the headway control prohibition flag F_CAIs set to “1” representing control prohibition. F_CA= 1, the process proceeds from step S103 to step S106 in the target vehicle speed setting process of FIG. 14, and the set vehicle speed V set by the driver is set._SETIs the target vehicle speed V^*And then proceeds to step S105, where the target vehicle speed V^*Is input to the target drive shaft torque calculating section 53, so that the following distance D becomes the following distance detection limit D._MAXEven when the vehicle speed is below, the follow-up cruise control does not operate, and the vehicle speed Vs is set to the set vehicle speed V set by the driver._SETThe traveling control is continued so as to match with.
[0063]
As described above, when it is determined that an impact that causes an optical axis shift has occurred, the optical axis shift amount Δθ is estimated, and the optical axis shift amount Δθ is set to a predetermined value Δθ._TH2Since the inter-vehicle distance control is prohibited when the distance is larger, it is possible to reliably prevent the following traveling control from being performed in a state in which the inter-vehicle distance to the preceding vehicle cannot be accurately recognized due to a large optical axis shift.
[0064]
On the other hand, the forward object sensor 18 supplies a predetermined value Δθ_TH2It is assumed that the vehicle is traveling with the following slight optical axis deviation. In this case, in the impact determination process of FIG. 15, in step S201, Δθ ≦ Δθ_TH2Is estimated. Since the optical axis adjustment is not performed at the maintenance shop or the store, the process shifts from step S202 to step S203, and the stored optical axis deviation amount Δθ is retained, and the optical axis deviation amount Δθ is changed to the optical axis deviation display threshold Δθ._SETIf the above is the case, the process proceeds to step S206 based on the determination in step S205, and the optical axis deviation display device 17 displays the optical axis deviation. Then, the process proceeds from step S207 to step S209, and as shown in FIG. 16, the inter-vehicle distance corresponding to the optical axis shift amount Δθ is the inter-vehicle distance detection limit D._MAXIs set as
[0065]
Inter-vehicle distance detection limit D with forward object sensor 18_MAXWhen the following distance D is detected and the own vehicle detects the preceding vehicle, in the target vehicle speed setting process of FIG. 14, the process proceeds from step S103 to step S104, and the following distance D is set to the target vehicle distance D.^*Vehicle speed V for following while keeping^*Is set, and then the process proceeds to step S105 to set the target vehicle speed V^*Is input to the target drive shaft torque calculation unit 53 to perform the following travel control.
[0066]
Here, the inter-vehicle distance detection limit D_MAXIs set to a smaller value as the optical axis shift amount Δθ is larger._TH1<Δθ ≦ Δθ_TH2In the case of, the follow-up running control is performed only for the vehicle whose relative positional relationship with the preceding vehicle is closer as compared with the case where there is no optical axis deviation.
As described above, in the fifth embodiment, when a change in the detection range occurs in the sensor due to, for example, a certain impact applied to the host vehicle and a shift in the mounting position of the sensor for recognizing the preceding vehicle, the change immediately occurs. Since this is detected and inter-vehicle distance control is prohibited, it is possible to reliably prevent the following cruise control from operating with the detection range of the sensor changing, and when the detection range has not changed, Since the normal follow-up running control is performed, the running control can be performed without the driver feeling uncomfortable.
[0067]
Further, as the amount of change in the detection range of the sensor for recognizing the preceding vehicle is larger, the inter-vehicle distance control is performed only on a vehicle whose relative positional relationship with the detected preceding vehicle is closer. Since the inter-vehicle distance control is performed even on a vehicle whose relative positional relationship with the preceding vehicle detected is larger than that in the case of a large vehicle, the position of the preceding vehicle can be detected without deteriorating the accuracy of the preceding vehicle position. Optimal inter-vehicle distance control can be performed according to the state of the range change.
[0068]
In addition, since the magnitude of the impact applied to the sensor for recognizing the preceding vehicle is detected using the acceleration signal of the acceleration sensor used for airbags, which are widely used, a new impact detection sensor is required. There is no need for installation, and cost increase can be reduced.
In the fifth embodiment, the case where the acceleration sensor is applied as the acceleration detecting means has been described. However, the present invention is not limited to this, and the acceleration may be calculated from the vehicle speed of the own vehicle detected by the vehicle speed sensor. It may be.
[0069]
Further, in the fifth embodiment, the case where the acceleration signal of the acceleration sensor is used in step S201 in the impact determination process of FIG. 15 has been described. However, the present invention is not limited to this. The change rate of the yaw rate detected by the yaw rate sensor may be used in the same manner as in step S221 in the second embodiment shown in FIG. 10, and the vehicle speed sensor may be used in step S201 as in step S231 in the third embodiment shown in FIG. The detected rate of change of the vehicle speed may be used. Further, in step S201, the inter-vehicle distance and the relative speed with respect to the preceding vehicle detected by the front object sensor as in step S241 in the fourth embodiment shown in FIG. It may be used.
[0070]
In the above embodiments, when it is determined in step S202 that the optical axis adjustment has been performed in the impact determination process of FIGS. 6, 9 to 11, and 15, the optical axis shift amount Δθ is determined in step S204. Has been described as being reset to “0”, but the present invention is not limited to this. After the detection range is determined to have changed due to a collision or the like, the detection trajectory of a conventional stationary object (a forward roadside delineator) is detected. When the vehicle travels a distance necessary for the detection range change determination process based on the above and no change in the detection range is detected, the stored optical axis shift amount Δθ may be reset to “0”.
[0071]
In each of the above embodiments, the optical axis shift amount Δθ is equal to the optical axis shift display threshold Δθ._SETIn the above description, a case has been described in which the optical axis deviation display device installed in the vehicle compartment immediately displays that the optical axis deviation state is present. However, the present invention is not limited to this. May be stored, and when a diagnostic device is connected at a maintenance shop, a store, or the like, the diagnostic device may indicate that the optical axis is deviated. Instead of displaying the optical axis deviation state on the monitor, the optical axis deviation state may be notified by a sound, a buzzer, or the like.
[0072]
Furthermore, in each of the above embodiments, the case where a laser radar is used as the front object sensor 14 has been described. However, the present invention is not limited to this, and another distance measuring device such as a millimeter wave radar may be applied. .
In each of the above embodiments, the case where the present invention is applied to a rear wheel drive vehicle has been described. However, the present invention can also be applied to a front wheel drive vehicle, and a case where the engine 2 is applied as a rotary drive source. Although described, the invention is not limited to this, and an electric motor can be applied. Further, the present invention can be applied to a hybrid vehicle using an engine and an electric motor.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a front object sensor.
FIG. 3 is a flowchart illustrating a braking control operation determination process executed by a traveling controller 20 according to the embodiment of the present invention.
FIG. 4 is an explanatory diagram of a lateral movement amount necessary for avoiding steering.
FIG. 5 is a diagram illustrating a relationship between a lateral movement amount and a time required for the lateral movement.
FIG. 6 is a flowchart illustrating an impact determination process according to the first embodiment.
FIG. 7 is a calculation map of an optical axis shift amount.
FIG. 8 is a diagram illustrating a relationship between an optical axis deviation amount and a braking control working distance.
FIG. 9 is a flowchart illustrating an impact determination process according to the second embodiment.
FIG. 10 is a flowchart illustrating an impact determination process according to the third embodiment.
FIG. 11 is a flowchart illustrating an impact determination process according to the fourth embodiment.
FIG. 12 is a schematic configuration diagram showing a fifth embodiment of the present invention.
FIG. 13 is a block diagram showing a specific example of the tracking controller of FIG. 12;
FIG. 14 is a flowchart showing a target vehicle speed setting process of a target vehicle speed setting unit of FIG. 13 in the fifth embodiment.
FIG. 15 is a flowchart illustrating an impact determination process according to the fifth embodiment.
FIG. 16 is a diagram illustrating a relationship between an optical axis shift amount and a detection distance between vehicles.
[Explanation of symbols]
2 Engine
3 automatic transmission
7 Disc brake
8 Brake control device
11 Engine output control device
13 Vehicle speed sensor
14 Forward object sensor
15 Acceleration sensor
16 Yaw rate sensor
17 Optical axis misalignment display device
20 Travel control controller
30 Tracking controller
50 Vehicle speed control unit
51 Target vehicle speed setting section
53 Target drive shaft torque calculator
60 Drive shaft torque control unit

Claims (9)

A vehicle comprising: front object detection means for detecting an object in front of the own vehicle; and travel control means for controlling travel of the own vehicle based on a relative positional relationship between the front object detected by the front object detection means and the own vehicle. In the travel control device for
An impact detecting means for detecting that an impact having a change in a detection range is applied to the front object detecting means; and the traveling control means when the impact detecting means detects that an impact is applied to the front object detecting means. A travel control prohibiting means for prohibiting travel control by the vehicle. A vehicle comprising: front object detection means for detecting an object in front of the own vehicle; and travel control means for controlling travel of the own vehicle based on a relative positional relationship between the front object detected by the front object detection means and the own vehicle. In the travel control device for
Shock detection means for detecting that an impact whose detection range changes is applied to the front object detection means; and detecting the front object when the impact detection means detects that an impact is applied to the front object detection means. A travel control device for a vehicle, comprising: a detection range change notification unit that notifies that the detection range of the unit has changed. A vehicle comprising: front object detection means for detecting an object in front of the own vehicle; and travel control means for controlling travel of the own vehicle based on a relative positional relationship between the front object detected by the front object detection means and the own vehicle. In the travel control device for
Shock detection means for detecting that an impact whose detection range changes is applied to the front object detection means; and detecting the front object when the impact detection means detects that an impact is applied to the front object detection means. A change amount estimating means for estimating a change amount of the detection range of the means; and a traveling control changing means for changing a control method by the traveling control means according to the change amount estimated by the change amount estimating means. Characteristic vehicle travel control device. 4. The vehicle according to claim 1, further comprising an acceleration detection unit configured to detect an acceleration of the vehicle, wherein the impact detection unit detects an impact using the acceleration detected by the acceleration detection unit. The travel control device for a vehicle according to any one of the above. 2. The vehicle according to claim 1, further comprising: a yaw rate detecting unit configured to detect a yaw rate generated in the host vehicle, wherein the impact detecting unit is configured to detect an impact using the yaw rate detected by the yaw rate detecting unit. The vehicle travel control device according to any one of claims 1 to 3. A vehicle speed detecting means for detecting a vehicle speed of the own vehicle, wherein the shock detecting means is configured to detect a shock using a change rate of the own vehicle speed detected by the vehicle speed detecting means. Item 4. The travel control device for a vehicle according to any one of Items 1 to 3. 4. The apparatus according to claim 1, wherein the shock detection unit is configured to detect a shock based on a relative positional relationship with the front object detected by the front object detection unit. 5. Travel control device for vehicles. A collision for determining whether to avoid collision by braking to the front object and to determine whether to avoid collision by steering based on the relative positional relationship with the front object detected by the front object detection means and the braking characteristics and steering characteristics of the own vehicle. Avoidance determining means, wherein the impact detecting means is configured to detect that an impact has occurred when the result of the collision avoidance determining means cannot avoid braking and steering avoidance. The vehicle travel control device according to any one of claims 1 to 3, wherein: The travel control changing means performs the travel control only for the relative position relationship with the front object is smaller as the change amount of the detection range estimated by the change amount estimating means is larger, and as the change amount is smaller, The vehicle travel control device according to claim 3, wherein the travel control is also performed for a vehicle having a large relative positional relationship with an object ahead as compared with a case where the amount of change is large.

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